1. Field of the Invention
The present invention relates to implantable medical devices, and more particularly, to recognition of implantable medical devices.
2. Related Art
Implantable hearing prostheses provide the benefit of hearing to individuals suffering from severe to profound sensorineural hearing loss. Sensorineural hearing loss is due to the absence or destruction of the hair cells in the cochlea which transduce acoustic signals into nerve impulses. An implantable hearing prosthesis essentially simulates the cochlear hair cells by delivering electrical stimulation to the auditory nerve fibers. This causes the brain to perceive a hearing sensation resembling the natural hearing sensation.
The present invention is particularly concerned with situations where a user, patient or recipient, “recipient” herein has an external processing device that communicates with an implanted device. For example, in a modern, conventional cochlear implant, an external speech processor transmits power and data to the implanted device via an inductive coil arrangement. The implanted device includes an electrode array to deliver the desired electrical stimuli to the cochlea of the recipient.
Once implanted, the implant system is typically adjusted to suit the specific needs of the recipient. As the dynamic range for electrical stimulation is relatively narrow and varies across recipients and electrodes, there is a need to individually tailor the characteristics of electrical stimulation for each recipient. This procedure, often referred to as “fitting,” “programming,” “mapping” (“mapping” herein) involves measuring and controlling the amount of electrical current delivered to the cochlea. Typically, a clinician, audiologist or other medical practitioner (generally and collectively referred to as “audiologist” herein) uses interactive software and computer hardware to create individualized programs, commands, data, settings, parameters, instructions, and/or other information (generally and collectively referred to as a “MAP” herein) that define the specific characteristics used to generate the electrical stimulation signals presented to the electrodes of the implanted electrode assembly. It is increasingly common for recipients to have a cochlear implant for each ear, which is commonly known as bilateral implantation. The advantages of bilateral implantation vary from recipient to recipient, and may include improved speech perception, and the ability to localize sounds. However, due to differences in the anatomy and physiology of recipients, and in the need to precisely place the electrode array, there will almost always be differences in the map between the left and right ears. The recipient will have two speech processor devices, each operating according to a different MAP. The speech processor devices are typically identical in appearance, and may inadvertently be swapped. This is a particular issue for very young and elderly recipients, as well as those with conditions such visual impairment. The use of the incorrect speech processor device will at best lead to reduced speech perception, as the incorrect MAP is applied, and potentially to pain for the recipient as excessive stimulation values are utilized for that ear.